650C vs 700c gearing

[amyp]

I currently have a Terry Tailwind I often find I'm a lot slower than riders around me. I get dropped on rides most of the time. :/
I feel like I am spinning out of control whenever I shift. Is there a way to change this or is it just me?

When I went to the velodrome they had a 650c track bike for rent and I often found I was spinning out of control as well - they used the same track gearing as the 700c bikes. I am assuming this is the same reason for me spinning out of control on my road bike. The gearing for 650c wheels and not 700c?

I've been finding it hard to find advice at bike shops since I have only found shops have 700c. I'd get a 700c if I could touch the ground and there was no toe overlap.

[Eden]

Wheel size does make a very small difference, but it's really pretty small. With all other things equal the speed difference between 700's and 650's at the same rpm's is 10ths of a mile per hour. You will have to spin a little faster on 650s than 700s at the exact same gear ratio to maintain the exact same speed, but not by so much that it should be particularly noticeable and definitely not so much that you are spinning wildly - it's probably only around 5rpm difference. You can check it out here: http://velobase.com/Resource_Tools/GearCalc.aspx

I have both bikes with 650s and 700s. My 650 has standard double road gearing, the same as my 700. I can't say I notice any difference riding the two. The 650 is the heavier of the bikes, so it's actually faster on descents…

[amyp]

The Terry Tailwind is from 2011 with the shimano 105 group set. There are two chainrings in the front.
Little one has 34t and 50t in the big ring. hopefully I didn't look at it incorrectly. 10 cogs in the back. It has 165mm cranks.

Sometimes I'm spinning in the big chainring when I'm on flats.
I don't have a bike computer that calculates my cadence either.
Hopefully these photos help.

[Crankin]

I've had bikes with both 650 and 700 wheels and there was no noticeable diference in my speed. When you are talking about "spinning," it sounds like this might be more of a gearing issue than what size wheels you have. I am a natural "spinner," in that my cadence is always high, I never stand or mash the pedals, and I tend to use the easiest gear I can, to give me the speed I want. But, you might feel that you need a gear that is in between the ones you have on the rear cog. When this happens, you can feel like one gear is too hard, but the next lowest one has you spinning like crazy. I felt like this when I switched from a triple to a compact double; there's bigger jumps in the gear ratios on a compact. I learned to get used to this by using the harder of the cogs and getting used to that. Four years later, it's not an issue and both my bikes have this kind of gearing. It sounds like your Terry has similar gearing, so you might try experimenting with using slightly different gear combos.

[OakLeaf]

I think maybe a cadence sensor might be a good idea, either that or just use a watch or computer with a seconds display, and count your cadence when you're in a safe, flat place and spinning at a cadence that you feel is "out of control." Everyone has a "powerband," a most efficient cadence range, that's different for everyone - but on the other hand, learning to pedal in circles rather than squares, is a neuromuscular skill that can improve with practice. It's one thing if you feel like you're out of control at 130 rpm ... a completely different thing if it's 70. Especially since you're feeling out of control in your big ring on the flats - and on a track bike, which are typically geared pretty tall - that suggests that you're pedaling inefficiently at a rather low cadence.

Make sure your bike is properly fit - that can make a huge difference - and it's certainly possible that even the 165 mm cranks are too long for you, which is a dilemma since it's very hard to find anything shorter. Me personally, I can't ride anything longer than 165 without causing both knee and Achilles tendon injury, besides it being much harder to spin, and I'm on a 50 cm frame (though that's a little bit large for me, and my tibia/femur ratio means I tend to need shorter cranks than most people with my overall inseam length).

Try looking up drills and form cues for pedaling efficiency. A couple of easy things to do are just simply visualizing pedaling in circles at a comfortable cadence, try to sense and eliminate any hitches or "angles" in your pedal stroke. Downhill intervals are a great drill - get to the top of the hill without working too hard, then coast down while pedaling in whatever gear allows you to just keep tension on the chain. A cadence sensor would also let you do cadence intervals on the flats - just spin up as high as you can without bouncing for one minute, then rest, then repeat.

Equipment issues are important, but don't overlook the neuromuscular issues.

[OakLeaf]

I just went back and re-read the OP also, and "if I could touch the ground" is a big red flag.

If you can touch the ground without leaning your bike over, on a road bike, then your seat height is too low. You'll never be able to pedal efficiently if you're not extending your legs, and even a very low cadence may well feel "out of control" if you're having to hyper-flex your knees and hips on each stroke. You don't want your knees fully extended at the bottom of your pedal stroke, but mostly so. A quick and dirty test is to set your seat at the height where, at the pedal's lowermost point and your leg fully extended but NOT clipped in, your heel just touches the pedal at the spindle center. Then when you move your foot back into pedaling position, there will be a slight bend in your knee. An illustration of some bike fitting basics is here.

If you've been riding with your seat much lower than that, then don't change it all at once. Small changes make a big difference in your biomechanics, so let your body adjust gradually. Raise your seatpost at most 3-4 mm each ride. Take as many rides as you need at any given seat height to adjust to the difference, before you raise it the next increment. Get comfortable with leaning the bike over when you come to a stop. Turning your handlebars slightly away from the foot you plan to touch down with, will help initiate a lean. While it's good to be able to touch down with either foot, IMO you'll have a smoother learning experience if you make a habit of always putting the same foot down, so you don't experience a moment of indecision. Then once you're completely comfortable and habituated to that foot, then you can start learning to put the other foot down instead.

Now, if I've misinterpreted what you meant by "touch the ground," then sorry for the misunderstanding ... I know that's the same phrase I use about motorcycle seat height when what I mean is that my leg strength and angle won't support the bike if I lean it over far enough to touch the ground, and/or I won't have enough straight line traction from the rear wheel to get it back moving again ... still it would be extremely unusual for a bicycle frame to fit your upper body properly, yet be so tall that your wheel is at any extreme lean angle when you're at a stop ...

[amyp]

i actually got fitted in January 2015 and it has improved a lot since. I definitely feel less fatigue. Got my cleats/pedals adjusted, saddle and saddle height. He said the fitting is guaranteed for a year- maybe I should go back? I do remember him asking me what my cadence was but I couldn't give him a clear answer - I guess I wasn't prepared for that.

When I'm at a stop on my 650c bike I can touch the ground but I am on my toes. I was saying if I was on a bike with 700c I can't touch the ground even if it had a 42cm frame.

Oh hahaha, I think the cross chain looks like that because I shifted to count the teeth on the chainring.

sorry I feel like I'm making this more difficult than it should be.

[Jolt]

Also, if you are on a group ride with a large rack on your bike, that will make it harder to keep up.

Only if the rack has a bunch of stuff on it...

[Crankin]

I have a 47 cm Trek Silque with 700 cc wheels. It's perfect. No toe overlap. Ten years ago, I had a Trek 5200 WSD 47 cm with 650 wheels. Both were fine... but I feel no need for 650 wheels now.